Grisaille

A type of decoration in painted enamel in which the picture or design in monochrome, usually shades of grey on a white ground.

The process involves first applying to the entire surface of a metal base a coating of dark enamel (usually black) that is then fired, after which the design is outlined and developed by successive
painting in shades of grey, white, and black, in varying thicknesses so that the design appears as if in relief.

Sometimes the monochrome is in shades of purple and brown.The leading exponents of the technique in the 16th cnetury were Nardon Pénicaud and Léonard Limousin of Limoges, France; they further extended
the technique by developing painted grisaille (tinted grisaille) in various shades and tints laid on over a greyish foundation.